GARDAI are trying to renegotiate a peace deal between the feuding Sheriff Street gangs this weekend -- amid threats of retaliation for the murder of Stephen 'Madser' Byrne.
Officers are desperately trying to keep a lid on simmering tensions in the north inner city, which have remained sky high since Byrne's murder last Tuesday.
The Herald understands that efforts are being made to negotiate a ceasefire between the two sides -- the Christy Griffin gang and their rivals.
Attempts at a pact come as officers made a fourth arrest, of a man in his 20s, last night.
Armed patrols are on standby in the area. In a short period there yesterday, the Herald witnessed a number of undercover units responding to an alert close to the Five Lamps -- but it appeared to be a false alarm.
Byrne was murdered by a lone gunman on a black mountain bike who rode up to him and shot him twice in broad daylight at St Lawrence O'Toole Place at 5pm last Tuesday.
Two youths, aged 15 and 16, and a man in his 20s, who were speaking with Byrne at the time, have already been arrested and released.
A peace deal was reportedly struck between the two Sheriff Street factions last year. But the period of calm broke down in February following a serious incident between the gangs. Efforts are now under way to revive the ceasefire.
A source told the Herald: "Tensions are so high at present that it's taking everything just to stop another murder.
"Both sides have been spoken with and officers are trying to calm things down."
Five people have been killed in the bloody inner city feud, which began following the rape by paedophile gang boss Christy Griffin of his partner's young daughter.
When the allegation emerged five years ago, Griffin's armed robbery and drug-dealing gang fell apart.
Some of his closest associates stayed loyal to Griffin while others broke away to form a rival group.
The two groups refused to sit down together but intermediaries brokered the deal last year, it is understood.
Detectives who were involved in the investigation into the murder of Anthony Russell had offered to act as mediators, but this was declined. Other intermediaries took their place to fashion the 2009 ceasefire.
Gardai are now attempting to make a similar approach.
Russell (30), of Cromcastle Drive, Kilmore, was gunned down as he sat drinking with friends in the Ardlea Inn in Artane.
Russell was close to Griffin and was believed to have been involved in the killing of Gerard 'Batt' Byrne, Stephen 'Madser' Byrne's cousin.
However, it's feared that the animosity that has been built up between the factions may be irreparable given the long history between the rival gangs.
The feud erupted in 2004 following allegations surrounding Christy Griffin and accusations of paedophilia.
In October 2005, shots were fired into Griffin's home in Swords, wounding him in the arm. Ensuing drive-by gun attacks saw Griffin's rape victim's home being shot at.
In November 2006, a hand grenade was thrown into Griffin's home and exploded.
Another grenade was then thrown into a relative's house, but failed to detonate. In December 2006, as Griffin's trial for rape approached, two men lost their lives in a fortnight.
The Emergency Response Unit and other armed gardai were called into the area around Sheriff Street and the IFSC to deter further attacks.
Two weeks later a gunman crept into a house on Oriel Street and shot Stephen Ledden (28) in the head as he lay on a sofa. He was shot by mistake by a killer targeting another man thought to be behind Gerard 'Batt' Byrne's murder.
The prime suspect in that murder was Stephen 'Madser' Byrne, who was shot dead last Tuesday.
Anthony Russell was killed in 2008 and another faction member was killed last February in another gun attack.
Gardai are continuing to appeal for information on the hitman, who cycled up to Stephen 'Madser' Byrne and shot him at least twice in broad daylight before escaping on his black bicycle.
Gardai had warned him on a number of occasions that his life was in danger and it is reported that there was a contract out on his life.
Byrne (32), a convicted criminal, lived at Mariner's Port, just yards from where he was killed. He received a phone call while in his house and went out to meet somebody on the street.
As he was talking to three men, a lone gunman approached on a mountain bike, shooting Byrne in the head and chest.